Nipah Virus Reappears 1 Year After Deadly Outbreak

The Indian state of Kerala is on high alert after a 23-year-old man was diagnosed with Nipah virus. CNN reports that 311 individuals in the area have been put under surveillance for the highly contagious disease and 4 of the 311 are displaying symptoms.

This newly confirmed case comes only a year after an outbreak affected 23 individuals and killed 21 of those people in the same region.

Nipah virus has a mortality rate of 40-75% and was first identified 2 decades ago in Malaysia. The 1998-1999 outbreak infected 300 people and, due to the risk of zoonotic transmissions, 1 million pigs were killed in order to stop the disease from spreading. The virus is typically spread by fruit bats to animals, such as pigs, which can, in turn, infect humans.

According to the World Health Organization, symptoms of Nipah virus include fever, headaches, dizziness, drowsiness, respiratory problems and, in severe cases, encephalitis and seizure, which can lead to a coma within 24 to 48 hours.

Currently, there is no preventive vaccine or drug to treat Nipah virus. However, remdesivir (GS-5734), a nucleotide analog prodrug currently being developed by Gilead Sciences, Inc., is showing promise. The drug, which was originally developed to protect against Ebola virus, completely protected 4 African Green monkeys from Nipah virus in a recent trial.

For the study, 8 monkeys were first infected with a lethal dose of Nipah virus. Then, the study team administered remdesivir intravenously to 4 monkeys 24 hours following inoculation. The monkeys then received another dose of the drug every day for the next 12 days. Two of the animals developed mild respiratory issues, however, both monkeys recovered within 3 weeks. The other 2 monkeys did not get sick at all, according to the National Institutes of Health.

The 4 monkeys who did not receive the remdesivir each developed a fatal disease within 8 days after showing signs of illness 4 days prior.

In the study’s report, published in Science Translational Medicine, the authors indicate that, “Remdesivir (GS-5734) protects African green monkeys from Nipah virus challenge.” According to the investigators, while the treatment results were promising a few key challenges exist. For example, the monkeys received treatment very soon after infection, and disease progression within humans is very rapid. When there was an outbreak of the virus in Bangladesh, the average time between onset of the virus and death was only 5 days.

The investigators note that another potential option has shown efficacy against Nipah Virus, monoclonal antibody m102.4. However, very few doses of the drug are currently available for use in humans. Because of this, the researchers state “potentially adding remdesivir to the repertoire of Nipah virus treatments would substantially improve preparedness for emergency response to future outbreaks.”

“Our findings strongly support using remdesivir in response to the next Nipah virus outbreak, either under compassionate use protocol or possible a randomized clinical trial protocol,” the authors write in their report.

If you want to stay up-to-date with the Nipah outbreak and other viral outbreaks, be sure to visit the Contagion® Outbreak Monitor.